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Discussion Starter · #1 ·
Hey,

I have a friend who has an older trek 6500 with deore shifter. And when it gets cold (<50) he starts having issues shifting( especially down shifting) it seems that the thumb shifter is not catching at all.

I have ZERO clue of what the problem could be, and ideas?

thanks
 

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If the shifter is not able to catch, The lubricant in it has worn down to its polymer thickener which becomes more like a glue than a lubricant when it gets cold. Unscrew the philips head screws on the cover of the thumb shifters and clean out the old junk with a rag, wire, or whatever it is you could possible remove the gunk with. You can replace that type of lubricant with nearly anything that is oil based and thick enough because of that specific components lack of internal exposure. I do recommend Park Tools Bearing grease or any bearing grease by Phil Wood.
 

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Vaginatarian
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look at the cable when you shift , is it moving the deraillier? you could have bad or dirty cables. if the cable sticks the shifter wont feel like its down shifting. if you unhook the cable from the deraillier the shifter should still shift, if not then it needs lube. DO NOT take it apart, I did that 1 time, as I opened the case I heard a zip noise and something flew out. after that it was toast. just open the cable port and squirt some chain lube in. I 've had good luck with finish line wet
 

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Meh.
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Take out the cable port, get something like White Lightning and just flush out the entire shifter. Use a little bit of Tri-Flow or some other LIGHT lube.

Make sure your cables aren't gunked up either.
 

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Using thin or thick lube is like asking whether imports or American cars are better. I prefer the thick stuff right now because its the middle of winter here in Massachusetts and it doesn't thin and wear off as quickly. During the summer, I do the thin teflon lubes due to its greater heat resistance capabilities. Remember how warm a seat belt buckle can get during the summer? Yeah. Same principle applies to engine oil weights in one way or another. Although thinner oils are used in colder weather. I prefer thicker lubes on the shifters because they aren't exposed to dirt in anyway compared to other bike components and its just easier to deal with when going outside isn't as much of a priority when its 17F out.
 

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Discussion Starter · #8 ·
dan0 said:
look at the cable when you shift , is it moving the deraillier? you could have bad or dirty cables. if the cable sticks the shifter wont feel like its down shifting. if you unhook the cable from the deraillier the shifter should still shift, if not then it needs lube. DO NOT take it apart, I did that 1 time, as I opened the case I heard a zip noise and something flew out. after that it was toast. just open the cable port and squirt some chain lube in. I 've had good luck with finish line wet
the cable does not move. when you press the thumb shifter nothing catches at all ...it acts like it is broke, but when it gets warmer it is fine. I am gonna mess with it tonight and see what happens.

thanks for the advise
 

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conjoinicorned
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the cable does not move. when you press the thumb shifter nothing catches at all ...it acts like it is broke, but when it gets warmer it is fine.
i've had this exact thing happen. carefully take the cover off the shifter (ther'es lots of springs and little parts), clean it very well, and lube with almost anything. works like a charm.
 

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Intense5point5 said:
Using thin or thick lube is like asking whether imports or American cars are better. I prefer the thick stuff right now because its the middle of winter here in Massachusetts and it doesn't thin and wear off as quickly. During the summer, I do the thin teflon lubes due to its greater heat resistance capabilities. Remember how warm a seat belt buckle can get during the summer? Yeah. Same principle applies to engine oil weights in one way or another. Although thinner oils are used in colder weather. I prefer thicker lubes on the shifters because they aren't exposed to dirt in anyway compared to other bike components and its just easier to deal with when going outside isn't as much of a priority when its 17F out.
well , finally a post that is completely wrong, every fact you listed is the opposite
thinner weight lubes flow better when its cold, heavier weight clings to parts better when its hot. how much heat resistance does a bike need? are you riding on the sun? or maybe the great cape cod desert.. Wheather or not the parts are exposed to dirt has nothing to do with viscosity. take some light oil, some heavy oil and some grease, put them on a dish and put them outside for an hour. Pick up the dish and turn it on its side, which one moves? ahhh the thinner one:thumbsup: , now ,which one would make your shifter move easier in the cold
I dont even know what your last sentence means:skep:
 
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